I have uses many different "signal mirrors over the last 4+ decades. Yes...Ican use even a tin can lide without even an aming hole.
I strongly prefer a laminated glass mirror with a aming grid.
Such mirrors as this one is such a mirror makes it extremely easy to use with only one hand...
I strongly recomend this and the smaller mirror as my first choice out of all the signal mirrors that I own and have used in the past
...a real solid 5-Star rateing !